This application requests a five-year renewal of the cooperative agreement 5-U01-HD19897 previously entitled "Chorionic Villus Sampling Vs Amniocentesis - Data Center". The renewal application entitled "NICHD Networks/Early Child Care Study: Coordinating Center" requests support for The George Washington University Biostatistics Center's ongoing activities associated with the National Institute of Child Health and Human Development (NICHD-NIH) Maternal Fetal Medicine Unit (MFMU) and Neonatal Intensive Care Unit (NICU) Networks and the proposed activities associated with the NICHD-NIH Early Child Care Study. Initiated in 1986, the NICHD MFMU and NICU Networks conduct clinical trials and epidemiologic studies in maternal-fetal medicine and obstetrics, and neonatal medicine, respectively. Currently, the 23 clinical centers associated with the Networks are implementing, executing or analyzing a total of 24 projects (10 randomized clinical trials, 2 pilot studies for proposed randomized clinical trials and 12 epidemiological studies). The Biostatistics Center has been funded as the MFMU and NICU Networks' Biostatistical Coordinating Center (BCC) since its inception. This renewal application also includes a proposal by The Biostatistics Center to serve as the Data and Statistical Coordinating Center (DSCC) for the NICHD-NIH funded Early Child Care Study. Implemented in 1991, the Early Child Care Study is a 10 site observational study of over 1300 young children designed to examine the effects of nonmaternal care, especially during the first year of life, on the child's social and intellectual development. The Biostatistics Center will provide statistical support and consultation in the areas of design, execution, close-out and analysis as they apply to the program of projects conducted by the Networks and the Early Child Care Study. Due to the scope of the program of projects, the application is organized into six sections: (1) budget justification for the Networks and the Early Child Care Study, (2) general technical proposal for the Networks, (3) specific technical proposal for the MFMU Network, (4) specific technical proposal for the NICU Network, (5) technical proposal for the Early Child Care Study, and (6) bibliography of the literature cited.